It might be objected that, in spite of Goethe’s greatness of mind, there was a supervenient morbid condition. But this assumption is directly contradicted by the fact that deceptions of sense are relatively frequent among famous men. Hence, even Moreau does not say that there is a supervenient disease by the side of, and in spite of, the mental greatness, but holds the latter to be itself a sign of incipient insanity.

I am therefore of the opinion that the sporadic sense deceptions of famous men, like other so-called “morbid symptoms of genius “ which we shall have to consider, can not be regarded as morbid symptoms, but that they are phenomena of health which it is the task of science to explain and account for.

The chief condition of mental sanity, as I have already several times remarked, is a well-proportioned development of the different psychical factors. But as in the development of the different mental faculties, so also in their proportion to one another, certain latitude of health is to be allowed. In one man fancy is preponderant; in another, consecutive thought; while a third may have particularly strong feelings as his characteristic. Yet we have no reason to say that these minds transgress the border of health. It is the difference in the relation of the different psychical elements that makes the diversity of men’s characters. Now we know that there are no two characters in the world that are precisely alike. It follows that there is no norm for these relations.

The higher the grade of development of the genius and of the individual, the more prominent will differences of psychical factors become, and a correspondingly greater latitude of health must be allowed. If a sculptor models a small statue, and in doing so makes a slight error, so that there is a difference between the two sides, probably it will strike nobody. But let the statuette be five times larger, and the difference will become prominent, though the proportions should remain the same. In like manner, for persons of the highest mental development—the so-called geniuses—we have to use a larger measure. They appear to us like ordinary men seen through a magnifying glass.

We now proceed to examine the different symptoms which have been discovered in great men, and to endeavour to ascertain the distinctions between these and symptoms of insanity.

Moreau and Lombroso have collected a large catalogue of famous men who are said to have experienced hallucinations. I will not enumerate them all, but among them are Napoleon, Luther, Bernadotte, Benvenuto Cellini, Byron, Cardanus, Cromwell, Socrates, Brutus, etc.